We do take him at set times of the day regardless of whether he needs to go i.e. wake up, before meals, 30mins after meals, before bath and bed. Even when he says he doesn't need to wee when we ask beforehand, he will still manage to wee on the toilet sometimes so thinking he still doesn't understand when he needs to go or not. He has also had 4 accidents on average during the day. Not sure what approach to take to teach him when he needs to go.
Perhaps he’s still a little young for the whole TT process to be making sense to him. Boys are generally slower than girls to become TT and some days, as you’re finding, it’s a non event and other days toddlers seem to forget everything they’ve ever learned.
The key is for parents to stay calm, be very matter of fact and just deal with the “accidents” in a non fussy way. Have you checked the Huggies website for specifics about TT?
Sometimes going back to nappies is a backwards step so if you’re considering this think twice. Especially in the summer months when there’s less washing and layers to deal with, TT becomes an easier process for everyone concerned.
There’s also value for toddlers to be taken to the toilet by their same gender parent so they see what’s involved. There’s no room for shyness here either, again, matter of fact and being practical help.